A unanimous US Supreme Court ruled Wednesday that police may not generally search the cellphones of people they arrest without first getting search warrants in an emphatic defence of digital age privacy.
Cellphones are powerful devices unlike anything else police may find on someone
they arrest, Chief Justice John Roberts said for the court. Because the phones contain so much information, police must get a warrant before looking through them, Roberts said.

“Modern cellphones are not just another technological convenience. With all they contain and all they may reveal, they hold for many Americans the privacies of life,” Roberts said.

The message to police about what they should do before rummaging through a cellphone’s contents following an arrest is simple. “Get a warrant,” Roberts said.

The chief justice acknowledged that barring searches would affect law enforcement, but said: “Privacy comes at a cost.” The court chose not to extend earlier rulings that allow police to empty a suspect’s pockets and examine whatever they find to ensure officers’ safety and prevent the destruction of evidence.

The Obama administration and the state of California, defending the cellphone searches, said cellphones should have no greater protection from a search than anything else police find.

But the defendants in these cases, backed by civil libertarians, librarians and news media groups, argued that cellphones, especially smartphones, are increasingly powerful computers that can store troves of sensitive personal information.